Clothing and accessory fashion brought about rapid changes in the direction of reduced use of heavy components and ornaments on items such as handbags, pocketbooks, attache cases, tobacco pouches, coin purses and similar soft cloth and leather products. In order to still effectively tightly close these new items without the use of an unsightly large clasp or zipper the so-called spring frame is ordinarily used. It consists generally of four components namely two mating spring steel hinge frames and two hinge pins. These parts are finally assembled at the time of completion of the article. For instance, each frame must be slipped into its individual pocket at each side of the intended handbag opening. Thereafter the hinge pin is inserted at each hinge. U.S. Pat. No. 2,903,033 discloses typical closure devices such as the frame, hinge and pin.
Conventional means for accomplishing this final assembly can take several forms. For instance, FIG. 1 illustrates an often used means consisting of a guide pin 10 and a rivet 12. The guide pin has a lower extended aligning tapered section 13, a cylindrical upper region 14, a platform 15 and a centering pin 16. The diameter and length of the centering pin are such that it snuggly occupies the provided recess of rivet 12 shown in cross section 17. The rivet is inserted onto the guide pin 19 and both are worked down into the hinge. The tapered section 13 aides in aligning the three hinge curls. The diameter of the guide pin at region 14 and rivet shank are the same. This allows for a smooth transition of the developing inherent tension as the wider upper diameter of the guide pin advances through the hinge from the guide pin onto the rivet. The height of the rivet is such that as the bottom of the rivet emerges from the hinge the guide pin no longer is tensionably held in communication with the rivet and by gravity drops off. Subsequently the reusable guide pin must be retrieved from the assembled product. The assembly is not considered complete because the rivet pin, under the tension and rotational movement of the working hinge about the inserted rivet could be caused to ride up out of the hinge and become dislodged. To avoid this problem, in an additional step, the rivet recess 17 is flared out by the action of an aligned anvil tip and hammer. Its radial dimension is thereby increased beyond that of the internal diameter of the spring hinge. This awkward flaring process, now inside the crowded end of the assembled piece, can result in the rivet flare interfering with full rotational movement about the rivet. Furthermore, if an error was made in the assembly it becomes difficult to remove the flared rivet.
Another method of final frame assembly calls for the use of a blunt nosed pin. The nose radius is typically that of the cylindrical upper portion of the hinge pin. Since there is no tapered aligning section in this pin the tension of the hinge is generally overcome by applying jaw pressure via a foot press to the hinge components. This squeezes them together, aligns the openings of the three curls and permits reduced effort in driving the leading hemisphere blunt nosed pin "home". Unfortunately under the action of the jaws used to align the hinge curl holes, problems can develop. Initially, the proper location for the jaws to be positioned is difficult to establish since the hinge is not generally visible this time being covered with non-transparent material, such as cloth, plastic or leather. Also an oversqueeze of the hinge develops a set in the tang spring thereby reducing its effective force. Once this type hinge pin has been inserted it usually is secured in place by a second procedure wherein the assembled piece must be first opened and then a cap nut is forced over the blunt nose. The cap nut can be held in place by a score line provided around the lower end of the hinge pin. If a strap, handle, etc. is to be used to carry the final item it is imperative that the pin be securely locked in place.
If only two of the three hinge curls are "caught" by the inserted pin it could go undetected as visually the misaligned bottom curl is hidden deeper within the recess of the assembled item. Obviously the hinge under that circumstance would be inoperable and/or damaged. Since the curls of conventional spring hinges are essentially cylindrical the opportunity exists for the aforementioned misalignment to occur.
Accordingly, it is therefore an object of the present invention to provide an improved method and apparatus for assembly of spring hinges and frames which will serve to avoid restricted rotational movement.
A further object of the invention is to allow for a single step assembly of spring hinges; eliminating the prior multi-step process.
An additional important object of the invention is to provide for a new unique hinge pin which is both self-aligning and self-locking, that becomes a part of the final assembly and does not require the use of any additional fastener or process.
Yet another object of the instant invention is to provide for audio confirmation that the new pin has been properly assembled in all the intended curl elements of the spring hinge.
Another object of the invention is to enable final assembly of the end product from the outside only thereby not necessitating entry into the completed item.
It is still a further object of the invention to provide for a spring hinge pin that is secure and self-locking yet can be disassembled easily and in a totally nondestructive manner.
Another object of the invention is to provide a spring hinge and pin which allows for a flush finish in the assembled parts.